Robert j



UNITED STATES PATENT OFFICE.

ROBERT J. EBERrs AND J. LAWRENCE LEE, OFNEW YORK, N. Y.; SAID EBERTS ASSIGNOR TO THE AMERICAN HEATING AND POWER COMPANY,

OF SAME PLACE.

NON-ABSORBING AND HEAT-INSULATING MATERIAL.

SPECIFICATION forming part of Letters Patent No. 266,954, dated October 31, 1882.

Application filed Septemherfi, 1882. (Nomodeh) 7 7/,

To all whom it may concern:

Be it known that we, ROBERT J. EBERTS and JOHN LAWRENCE LEE,of the city, county, and State of New York, have made a new and useful invention ofa Non-Absorbing and Heat- Insulating Material, which may be used as an inclosing envelope for steam or other pipes, which material at the same time provides protection against moisture and conduction of heat, of which the following isa specification.

\Vcmanuiacture our heat-insulator and nonabsoi'bing concrete material in the following way: As the first ingredient of the new compound we employ spent tan bark. The requirements of this ingredient of our composition are that it should be a non-conductor of heat itself, should be capable of fine division, and should also be capable of receiving and retaining a coating of some liquid or semiliquid material. When we use tan-bark we dry the material in a kiln preferably, orin any other desired way, the heat employed being suflicient to drive ofi' all moisture, while at the same time the heat must not be so great as to injure the material. We find it best to use the material in pieces of about the third of an inch in each dimension, though larger or smaller pieces will do, but not so Wells After the spent tan-bark has been thoroughly dried it is necessary to treat it with some substance which will make it water-proof and preserve it from decay, and this treatment is best accomplished by coating the surface of the pieces of tan-bark with tar and asphalt made liquid by heat. We do not confine ourselves to,this particular method or to these materials for rendering the tan-bark Water-proof and preventingitfrom decaying. -Wheu we use tar and asphalt we find that good results are obtained by using in bulk equal parts of tar and asphalt and in bulk as much tan-bark as the two portions of tar and asphalt combined. We thoroughly incorporate this mixture, while hot, by stirring, the heat being suflicient to keep the tar and asphalt liquid, while it is not sutficient to injure anyotl'the ingredients of the mixture. The result-of this mixture will be pieces of tanbark coated with tar and asphalt. To more certainly prevent the adherence of the pieces of tan-bark, a little plaster maybe stirred into the composition before it-becoines completely cool, sufiicient plaster being added merely to deprive each of the coated particles of tau-bark oftheiradherentqnalities. Thismixtnre,when made, can be keptiu barrels until it is desired to form with it and with the material which will be further on described our insulating and water-proof compound; but it may, if desired,

be immediatelymixed with some material or materials which will cause itto set and become hard. To accomplish this purpose we have found it best to use hydraulic cement-such as Portland or Rosendale cement-clean sharp building-sand, and evenlyground alabaster or plaster-of-paris, together with a snfiicient amount of water to give the mass a plastic con dition. We have found the best proportions to be equal parts of cement, sand, and alabaster, the bulk ofthe three materials as a whole being about equal to the bulk of the tan-bark, 7o tar, and asphalt after having been mixed. We, however, do not confine ourselves to this particular compound as a setting or binding material,as other materials which it ill setor bindas willcement and sand or plaster-will give a good result. Neither do we confine ourselves to the particular amounts of materials above stated, as good results can be obtained even if these amounts arevaried, and itmay be undo! certain circumstances necessary to vary the amounts for producing articles having conditions suited to different purposes. A sufiicient amount of water is to be used when the tan-bark covered with tar and asphalt is to be mixed with the setting or binding materials to make the mass plastic; but no more water is to be used than is necessary for accomplishing this result. Even when the tan-bark covered with the tar and asphalt is still hot the mixture may be made with the setting material or go materials; but we consider it best to allow the tan-bark coated with the tar and asphalt to cool before we mix it with the materials made plastic by water.

, Immediately at er all the materials are mixed and incorf/t iratcd one with the other, and before they are given time to set, the compound is ready to apply to the surface to be insulated and protected. Take, for examlo, a steam-pipe ,placed below theground. n this situation a wooden box may be made 4 'Il'bich surrounds the steam'pipe', and of sufii- 'cient size to give the required thickness be-' tween the inside of the'box and the surface "of'the pipe or pipes to be insulated for the insulating material, and this maybe from two to sixjnches. The plastic compound is packed 1 in this box aroundthe pipe, and is then allowed to set, the superfluous moisture either being .eraporatednaturally or being driven oil by the heat otlhe pipe or pipes insulated.

' In some cases it is advisable to apply paper or hair-felt to the pipe before the insulating and water-proof compound is placed around it. "The'ma'terial is put into the box around the pipe whilein its plastic condition, which condition is due to the water, as above described. 'Ihe'mass is then we'll rammed into. the box around the pipe, precisely as concrete The mawould be applied in a like situation. terial in a short time sets and becomes hard, when it will be found that it will possess a certain degree of elasticity. It greater elasticity and tenacity are desired in the resultingarticle, hair, fine wire, or suitable fibrous materialmay be stirred into and thoroughly incorporated with the compound while plastic, and it is well 'not to use as much hair or fibrous material as is ordinarily used in the mixing of building-mortar, and we find it best. to use a better and stronger quality of fiber than is- .used with mortar.

are liable to'more by reason of the expansion ot'the pipes, sufficient roo'm must be left between the material and the pipes to allow for this movement, and in the case of plain smooth pipes it is well to use a paper or hair felt which will furnish a SllffiClGlli'r space between the pipe and the insulating material to allow ofthe motions of expansion, and should.

the paper or felt be burned away an airspace will be left. Our material while still plastic some may be compressed in hydraulic or other presses, and may then, after being removed from'the mold, be allowed to set, or it may be .allowed to set while under compression. In

this way'very compact, durable heat-insulating and non-absorbent compositions will be produced,ificapable of igniting, and suitable for lining walls, partitions, &c;, or for paving cellars and the like, in which latter event it is desirable to set the blocks of compressed composition in asphalt.

The leading features of our composition are the spent tan-bark, dried and coated with a water-proof and preserving coating, and then the mixing of this compound with a material capable of setting, which will enable it to be placed around the article to be insulated, and then hardened whilein position.

What we claim, and desire to secure by Letters Patent, is-

1. The heat-insulating and water repelling material herein described, consisting of finelydivided tan-bark, dried and coated with a suitable waterproofing material and mixed with cement, sand, &c., or other material 0 materials capable of setting. 2. The process of making the heat-insulating and water-repelling material herein described, which consists of, first, drying finelydivided tan-bark, then, second, coating it with a water-proof material, then, third, ot'mixing with a suitable mass formed of materials capable of setting the prepared tan-bark, and, lastly, permitting the mass to set around the article to be insulated and protected.

3. As a heat-insulating and water-repellent material for packing steam-pipes and similar purposes, finely-divided tan-bark coated with tar and asphalt and embedded in cement, substantially as described.

4. 'A concrete for incasing steam or hotwater mains or for similar uses, composed of finely-divided tan-bark having the individual particles coated with water-proof material, compacted into a solid mass with cement by means of compression, substantially as described; b

5. As a heat-insulating and water-proof material, the admixture of tan-bark and tar and asphalt and hair or other'fiber, substantially as described.

ROBERT J. EBERTS. J. LAWRENCE LEE. Witnesses:

JOHN S. MORRISON, JOHN Ill-.CLURE, 

